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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network198.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
198.0.0.0
Broadcast address
198.255.255.255
First usable
198.0.0.1
Last usable
198.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
C (default /24)
As numbers
Hex C6000000 · Integer 3321888768 to 3338665983
Reverse DNS zone
198.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000110..00000000.00000000.00000000198.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11000110..00000000.00000000.00000000198.0.0.0
Broadcast11000110..11111111.11111111.11111111198.255.255.255
Split into smaller subnets/19
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

198.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1198.0.0.0/19198.0.0.1 to 198.0.31.254198.0.31.2558,190
2198.0.32.0/19198.0.32.1 to 198.0.63.254198.0.63.2558,190
3198.0.64.0/19198.0.64.1 to 198.0.95.254198.0.95.2558,190
4198.0.96.0/19198.0.96.1 to 198.0.127.254198.0.127.2558,190
5198.0.128.0/19198.0.128.1 to 198.0.159.254198.0.159.2558,190
6198.0.160.0/19198.0.160.1 to 198.0.191.254198.0.191.2558,190
7198.0.192.0/19198.0.192.1 to 198.0.223.254198.0.223.2558,190
8198.0.224.0/19198.0.224.1 to 198.0.255.254198.0.255.2558,190
9198.1.0.0/19198.1.0.1 to 198.1.31.254198.1.31.2558,190
10198.1.32.0/19198.1.32.1 to 198.1.63.254198.1.63.2558,190
11198.1.64.0/19198.1.64.1 to 198.1.95.254198.1.95.2558,190
12198.1.96.0/19198.1.96.1 to 198.1.127.254198.1.127.2558,190
13198.1.128.0/19198.1.128.1 to 198.1.159.254198.1.159.2558,190
14198.1.160.0/19198.1.160.1 to 198.1.191.254198.1.191.2558,190
15198.1.192.0/19198.1.192.1 to 198.1.223.254198.1.223.2558,190
16198.1.224.0/19198.1.224.1 to 198.1.255.254198.1.255.2558,190
17198.2.0.0/19198.2.0.1 to 198.2.31.254198.2.31.2558,190
18198.2.32.0/19198.2.32.1 to 198.2.63.254198.2.63.2558,190
19198.2.64.0/19198.2.64.1 to 198.2.95.254198.2.95.2558,190
20198.2.96.0/19198.2.96.1 to 198.2.127.254198.2.127.2558,190
21198.2.128.0/19198.2.128.1 to 198.2.159.254198.2.159.2558,190
22198.2.160.0/19198.2.160.1 to 198.2.191.254198.2.191.2558,190
23198.2.192.0/19198.2.192.1 to 198.2.223.254198.2.223.2558,190
24198.2.224.0/19198.2.224.1 to 198.2.255.254198.2.255.2558,190
25198.3.0.0/19198.3.0.1 to 198.3.31.254198.3.31.2558,190
26198.3.32.0/19198.3.32.1 to 198.3.63.254198.3.63.2558,190
27198.3.64.0/19198.3.64.1 to 198.3.95.254198.3.95.2558,190
28198.3.96.0/19198.3.96.1 to 198.3.127.254198.3.127.2558,190
29198.3.128.0/19198.3.128.1 to 198.3.159.254198.3.159.2558,190
30198.3.160.0/19198.3.160.1 to 198.3.191.254198.3.191.2558,190
31198.3.192.0/19198.3.192.1 to 198.3.223.254198.3.223.2558,190
32198.3.224.0/19198.3.224.1 to 198.3.255.254198.3.255.2558,190
33198.4.0.0/19198.4.0.1 to 198.4.31.254198.4.31.2558,190
34198.4.32.0/19198.4.32.1 to 198.4.63.254198.4.63.2558,190
35198.4.64.0/19198.4.64.1 to 198.4.95.254198.4.95.2558,190
36198.4.96.0/19198.4.96.1 to 198.4.127.254198.4.127.2558,190
37198.4.128.0/19198.4.128.1 to 198.4.159.254198.4.159.2558,190
38198.4.160.0/19198.4.160.1 to 198.4.191.254198.4.191.2558,190
39198.4.192.0/19198.4.192.1 to 198.4.223.254198.4.223.2558,190
40198.4.224.0/19198.4.224.1 to 198.4.255.254198.4.255.2558,190
41198.5.0.0/19198.5.0.1 to 198.5.31.254198.5.31.2558,190
42198.5.32.0/19198.5.32.1 to 198.5.63.254198.5.63.2558,190
43198.5.64.0/19198.5.64.1 to 198.5.95.254198.5.95.2558,190
44198.5.96.0/19198.5.96.1 to 198.5.127.254198.5.127.2558,190
45198.5.128.0/19198.5.128.1 to 198.5.159.254198.5.159.2558,190
46198.5.160.0/19198.5.160.1 to 198.5.191.254198.5.191.2558,190
47198.5.192.0/19198.5.192.1 to 198.5.223.254198.5.223.2558,190
48198.5.224.0/19198.5.224.1 to 198.5.255.254198.5.255.2558,190
49198.6.0.0/19198.6.0.1 to 198.6.31.254198.6.31.2558,190
50198.6.32.0/19198.6.32.1 to 198.6.63.254198.6.63.2558,190
51198.6.64.0/19198.6.64.1 to 198.6.95.254198.6.95.2558,190
52198.6.96.0/19198.6.96.1 to 198.6.127.254198.6.127.2558,190
53198.6.128.0/19198.6.128.1 to 198.6.159.254198.6.159.2558,190
54198.6.160.0/19198.6.160.1 to 198.6.191.254198.6.191.2558,190
55198.6.192.0/19198.6.192.1 to 198.6.223.254198.6.223.2558,190
56198.6.224.0/19198.6.224.1 to 198.6.255.254198.6.255.2558,190
57198.7.0.0/19198.7.0.1 to 198.7.31.254198.7.31.2558,190
58198.7.32.0/19198.7.32.1 to 198.7.63.254198.7.63.2558,190
59198.7.64.0/19198.7.64.1 to 198.7.95.254198.7.95.2558,190
60198.7.96.0/19198.7.96.1 to 198.7.127.254198.7.127.2558,190
61198.7.128.0/19198.7.128.1 to 198.7.159.254198.7.159.2558,190
62198.7.160.0/19198.7.160.1 to 198.7.191.254198.7.191.2558,190
63198.7.192.0/19198.7.192.1 to 198.7.223.254198.7.223.2558,190
64198.7.224.0/19198.7.224.1 to 198.7.255.254198.7.255.2558,190
65198.8.0.0/19198.8.0.1 to 198.8.31.254198.8.31.2558,190
66198.8.32.0/19198.8.32.1 to 198.8.63.254198.8.63.2558,190
67198.8.64.0/19198.8.64.1 to 198.8.95.254198.8.95.2558,190
68198.8.96.0/19198.8.96.1 to 198.8.127.254198.8.127.2558,190
69198.8.128.0/19198.8.128.1 to 198.8.159.254198.8.159.2558,190
70198.8.160.0/19198.8.160.1 to 198.8.191.254198.8.191.2558,190
71198.8.192.0/19198.8.192.1 to 198.8.223.254198.8.223.2558,190
72198.8.224.0/19198.8.224.1 to 198.8.255.254198.8.255.2558,190
73198.9.0.0/19198.9.0.1 to 198.9.31.254198.9.31.2558,190
74198.9.32.0/19198.9.32.1 to 198.9.63.254198.9.63.2558,190
75198.9.64.0/19198.9.64.1 to 198.9.95.254198.9.95.2558,190
76198.9.96.0/19198.9.96.1 to 198.9.127.254198.9.127.2558,190
77198.9.128.0/19198.9.128.1 to 198.9.159.254198.9.159.2558,190
78198.9.160.0/19198.9.160.1 to 198.9.191.254198.9.191.2558,190
79198.9.192.0/19198.9.192.1 to 198.9.223.254198.9.223.2558,190
80198.9.224.0/19198.9.224.1 to 198.9.255.254198.9.255.2558,190
81198.10.0.0/19198.10.0.1 to 198.10.31.254198.10.31.2558,190
82198.10.32.0/19198.10.32.1 to 198.10.63.254198.10.63.2558,190
83198.10.64.0/19198.10.64.1 to 198.10.95.254198.10.95.2558,190
84198.10.96.0/19198.10.96.1 to 198.10.127.254198.10.127.2558,190
85198.10.128.0/19198.10.128.1 to 198.10.159.254198.10.159.2558,190
86198.10.160.0/19198.10.160.1 to 198.10.191.254198.10.191.2558,190
87198.10.192.0/19198.10.192.1 to 198.10.223.254198.10.223.2558,190
88198.10.224.0/19198.10.224.1 to 198.10.255.254198.10.255.2558,190
89198.11.0.0/19198.11.0.1 to 198.11.31.254198.11.31.2558,190
90198.11.32.0/19198.11.32.1 to 198.11.63.254198.11.63.2558,190
91198.11.64.0/19198.11.64.1 to 198.11.95.254198.11.95.2558,190
92198.11.96.0/19198.11.96.1 to 198.11.127.254198.11.127.2558,190
93198.11.128.0/19198.11.128.1 to 198.11.159.254198.11.159.2558,190
94198.11.160.0/19198.11.160.1 to 198.11.191.254198.11.191.2558,190
95198.11.192.0/19198.11.192.1 to 198.11.223.254198.11.223.2558,190
96198.11.224.0/19198.11.224.1 to 198.11.255.254198.11.255.2558,190
97198.12.0.0/19198.12.0.1 to 198.12.31.254198.12.31.2558,190
98198.12.32.0/19198.12.32.1 to 198.12.63.254198.12.63.2558,190
99198.12.64.0/19198.12.64.1 to 198.12.95.254198.12.95.2558,190
100198.12.96.0/19198.12.96.1 to 198.12.127.254198.12.127.2558,190
101198.12.128.0/19198.12.128.1 to 198.12.159.254198.12.159.2558,190
102198.12.160.0/19198.12.160.1 to 198.12.191.254198.12.191.2558,190
103198.12.192.0/19198.12.192.1 to 198.12.223.254198.12.223.2558,190
104198.12.224.0/19198.12.224.1 to 198.12.255.254198.12.255.2558,190
105198.13.0.0/19198.13.0.1 to 198.13.31.254198.13.31.2558,190
106198.13.32.0/19198.13.32.1 to 198.13.63.254198.13.63.2558,190
107198.13.64.0/19198.13.64.1 to 198.13.95.254198.13.95.2558,190
108198.13.96.0/19198.13.96.1 to 198.13.127.254198.13.127.2558,190
109198.13.128.0/19198.13.128.1 to 198.13.159.254198.13.159.2558,190
110198.13.160.0/19198.13.160.1 to 198.13.191.254198.13.191.2558,190
111198.13.192.0/19198.13.192.1 to 198.13.223.254198.13.223.2558,190
112198.13.224.0/19198.13.224.1 to 198.13.255.254198.13.255.2558,190
113198.14.0.0/19198.14.0.1 to 198.14.31.254198.14.31.2558,190
114198.14.32.0/19198.14.32.1 to 198.14.63.254198.14.63.2558,190
115198.14.64.0/19198.14.64.1 to 198.14.95.254198.14.95.2558,190
116198.14.96.0/19198.14.96.1 to 198.14.127.254198.14.127.2558,190
117198.14.128.0/19198.14.128.1 to 198.14.159.254198.14.159.2558,190
118198.14.160.0/19198.14.160.1 to 198.14.191.254198.14.191.2558,190
119198.14.192.0/19198.14.192.1 to 198.14.223.254198.14.223.2558,190
120198.14.224.0/19198.14.224.1 to 198.14.255.254198.14.255.2558,190
121198.15.0.0/19198.15.0.1 to 198.15.31.254198.15.31.2558,190
122198.15.32.0/19198.15.32.1 to 198.15.63.254198.15.63.2558,190
123198.15.64.0/19198.15.64.1 to 198.15.95.254198.15.95.2558,190
124198.15.96.0/19198.15.96.1 to 198.15.127.254198.15.127.2558,190
125198.15.128.0/19198.15.128.1 to 198.15.159.254198.15.159.2558,190
126198.15.160.0/19198.15.160.1 to 198.15.191.254198.15.191.2558,190
127198.15.192.0/19198.15.192.1 to 198.15.223.254198.15.223.2558,190
128198.15.224.0/19198.15.224.1 to 198.15.255.254198.15.255.2558,190
129198.16.0.0/19198.16.0.1 to 198.16.31.254198.16.31.2558,190
130198.16.32.0/19198.16.32.1 to 198.16.63.254198.16.63.2558,190
131198.16.64.0/19198.16.64.1 to 198.16.95.254198.16.95.2558,190
132198.16.96.0/19198.16.96.1 to 198.16.127.254198.16.127.2558,190
133198.16.128.0/19198.16.128.1 to 198.16.159.254198.16.159.2558,190
134198.16.160.0/19198.16.160.1 to 198.16.191.254198.16.191.2558,190
135198.16.192.0/19198.16.192.1 to 198.16.223.254198.16.223.2558,190
136198.16.224.0/19198.16.224.1 to 198.16.255.254198.16.255.2558,190
137198.17.0.0/19198.17.0.1 to 198.17.31.254198.17.31.2558,190
138198.17.32.0/19198.17.32.1 to 198.17.63.254198.17.63.2558,190
139198.17.64.0/19198.17.64.1 to 198.17.95.254198.17.95.2558,190
140198.17.96.0/19198.17.96.1 to 198.17.127.254198.17.127.2558,190
141198.17.128.0/19198.17.128.1 to 198.17.159.254198.17.159.2558,190
142198.17.160.0/19198.17.160.1 to 198.17.191.254198.17.191.2558,190
143198.17.192.0/19198.17.192.1 to 198.17.223.254198.17.223.2558,190
144198.17.224.0/19198.17.224.1 to 198.17.255.254198.17.255.2558,190
145198.18.0.0/19198.18.0.1 to 198.18.31.254198.18.31.2558,190
146198.18.32.0/19198.18.32.1 to 198.18.63.254198.18.63.2558,190
147198.18.64.0/19198.18.64.1 to 198.18.95.254198.18.95.2558,190
148198.18.96.0/19198.18.96.1 to 198.18.127.254198.18.127.2558,190
149198.18.128.0/19198.18.128.1 to 198.18.159.254198.18.159.2558,190
150198.18.160.0/19198.18.160.1 to 198.18.191.254198.18.191.2558,190
151198.18.192.0/19198.18.192.1 to 198.18.223.254198.18.223.2558,190
152198.18.224.0/19198.18.224.1 to 198.18.255.254198.18.255.2558,190
153198.19.0.0/19198.19.0.1 to 198.19.31.254198.19.31.2558,190
154198.19.32.0/19198.19.32.1 to 198.19.63.254198.19.63.2558,190
155198.19.64.0/19198.19.64.1 to 198.19.95.254198.19.95.2558,190
156198.19.96.0/19198.19.96.1 to 198.19.127.254198.19.127.2558,190
157198.19.128.0/19198.19.128.1 to 198.19.159.254198.19.159.2558,190
158198.19.160.0/19198.19.160.1 to 198.19.191.254198.19.191.2558,190
159198.19.192.0/19198.19.192.1 to 198.19.223.254198.19.223.2558,190
160198.19.224.0/19198.19.224.1 to 198.19.255.254198.19.255.2558,190
161198.20.0.0/19198.20.0.1 to 198.20.31.254198.20.31.2558,190
162198.20.32.0/19198.20.32.1 to 198.20.63.254198.20.63.2558,190
163198.20.64.0/19198.20.64.1 to 198.20.95.254198.20.95.2558,190
164198.20.96.0/19198.20.96.1 to 198.20.127.254198.20.127.2558,190
165198.20.128.0/19198.20.128.1 to 198.20.159.254198.20.159.2558,190
166198.20.160.0/19198.20.160.1 to 198.20.191.254198.20.191.2558,190
167198.20.192.0/19198.20.192.1 to 198.20.223.254198.20.223.2558,190
168198.20.224.0/19198.20.224.1 to 198.20.255.254198.20.255.2558,190
169198.21.0.0/19198.21.0.1 to 198.21.31.254198.21.31.2558,190
170198.21.32.0/19198.21.32.1 to 198.21.63.254198.21.63.2558,190
171198.21.64.0/19198.21.64.1 to 198.21.95.254198.21.95.2558,190
172198.21.96.0/19198.21.96.1 to 198.21.127.254198.21.127.2558,190
173198.21.128.0/19198.21.128.1 to 198.21.159.254198.21.159.2558,190
174198.21.160.0/19198.21.160.1 to 198.21.191.254198.21.191.2558,190
175198.21.192.0/19198.21.192.1 to 198.21.223.254198.21.223.2558,190
176198.21.224.0/19198.21.224.1 to 198.21.255.254198.21.255.2558,190
177198.22.0.0/19198.22.0.1 to 198.22.31.254198.22.31.2558,190
178198.22.32.0/19198.22.32.1 to 198.22.63.254198.22.63.2558,190
179198.22.64.0/19198.22.64.1 to 198.22.95.254198.22.95.2558,190
180198.22.96.0/19198.22.96.1 to 198.22.127.254198.22.127.2558,190
181198.22.128.0/19198.22.128.1 to 198.22.159.254198.22.159.2558,190
182198.22.160.0/19198.22.160.1 to 198.22.191.254198.22.191.2558,190
183198.22.192.0/19198.22.192.1 to 198.22.223.254198.22.223.2558,190
184198.22.224.0/19198.22.224.1 to 198.22.255.254198.22.255.2558,190
185198.23.0.0/19198.23.0.1 to 198.23.31.254198.23.31.2558,190
186198.23.32.0/19198.23.32.1 to 198.23.63.254198.23.63.2558,190
187198.23.64.0/19198.23.64.1 to 198.23.95.254198.23.95.2558,190
188198.23.96.0/19198.23.96.1 to 198.23.127.254198.23.127.2558,190
189198.23.128.0/19198.23.128.1 to 198.23.159.254198.23.159.2558,190
190198.23.160.0/19198.23.160.1 to 198.23.191.254198.23.191.2558,190
191198.23.192.0/19198.23.192.1 to 198.23.223.254198.23.223.2558,190
192198.23.224.0/19198.23.224.1 to 198.23.255.254198.23.255.2558,190
193198.24.0.0/19198.24.0.1 to 198.24.31.254198.24.31.2558,190
194198.24.32.0/19198.24.32.1 to 198.24.63.254198.24.63.2558,190
195198.24.64.0/19198.24.64.1 to 198.24.95.254198.24.95.2558,190
196198.24.96.0/19198.24.96.1 to 198.24.127.254198.24.127.2558,190
197198.24.128.0/19198.24.128.1 to 198.24.159.254198.24.159.2558,190
198198.24.160.0/19198.24.160.1 to 198.24.191.254198.24.191.2558,190
199198.24.192.0/19198.24.192.1 to 198.24.223.254198.24.223.2558,190
200198.24.224.0/19198.24.224.1 to 198.24.255.254198.24.255.2558,190
201198.25.0.0/19198.25.0.1 to 198.25.31.254198.25.31.2558,190
202198.25.32.0/19198.25.32.1 to 198.25.63.254198.25.63.2558,190
203198.25.64.0/19198.25.64.1 to 198.25.95.254198.25.95.2558,190
204198.25.96.0/19198.25.96.1 to 198.25.127.254198.25.127.2558,190
205198.25.128.0/19198.25.128.1 to 198.25.159.254198.25.159.2558,190
206198.25.160.0/19198.25.160.1 to 198.25.191.254198.25.191.2558,190
207198.25.192.0/19198.25.192.1 to 198.25.223.254198.25.223.2558,190
208198.25.224.0/19198.25.224.1 to 198.25.255.254198.25.255.2558,190
209198.26.0.0/19198.26.0.1 to 198.26.31.254198.26.31.2558,190
210198.26.32.0/19198.26.32.1 to 198.26.63.254198.26.63.2558,190
211198.26.64.0/19198.26.64.1 to 198.26.95.254198.26.95.2558,190
212198.26.96.0/19198.26.96.1 to 198.26.127.254198.26.127.2558,190
213198.26.128.0/19198.26.128.1 to 198.26.159.254198.26.159.2558,190
214198.26.160.0/19198.26.160.1 to 198.26.191.254198.26.191.2558,190
215198.26.192.0/19198.26.192.1 to 198.26.223.254198.26.223.2558,190
216198.26.224.0/19198.26.224.1 to 198.26.255.254198.26.255.2558,190
217198.27.0.0/19198.27.0.1 to 198.27.31.254198.27.31.2558,190
218198.27.32.0/19198.27.32.1 to 198.27.63.254198.27.63.2558,190
219198.27.64.0/19198.27.64.1 to 198.27.95.254198.27.95.2558,190
220198.27.96.0/19198.27.96.1 to 198.27.127.254198.27.127.2558,190
221198.27.128.0/19198.27.128.1 to 198.27.159.254198.27.159.2558,190
222198.27.160.0/19198.27.160.1 to 198.27.191.254198.27.191.2558,190
223198.27.192.0/19198.27.192.1 to 198.27.223.254198.27.223.2558,190
224198.27.224.0/19198.27.224.1 to 198.27.255.254198.27.255.2558,190
225198.28.0.0/19198.28.0.1 to 198.28.31.254198.28.31.2558,190
226198.28.32.0/19198.28.32.1 to 198.28.63.254198.28.63.2558,190
227198.28.64.0/19198.28.64.1 to 198.28.95.254198.28.95.2558,190
228198.28.96.0/19198.28.96.1 to 198.28.127.254198.28.127.2558,190
229198.28.128.0/19198.28.128.1 to 198.28.159.254198.28.159.2558,190
230198.28.160.0/19198.28.160.1 to 198.28.191.254198.28.191.2558,190
231198.28.192.0/19198.28.192.1 to 198.28.223.254198.28.223.2558,190
232198.28.224.0/19198.28.224.1 to 198.28.255.254198.28.255.2558,190
233198.29.0.0/19198.29.0.1 to 198.29.31.254198.29.31.2558,190
234198.29.32.0/19198.29.32.1 to 198.29.63.254198.29.63.2558,190
235198.29.64.0/19198.29.64.1 to 198.29.95.254198.29.95.2558,190
236198.29.96.0/19198.29.96.1 to 198.29.127.254198.29.127.2558,190
237198.29.128.0/19198.29.128.1 to 198.29.159.254198.29.159.2558,190
238198.29.160.0/19198.29.160.1 to 198.29.191.254198.29.191.2558,190
239198.29.192.0/19198.29.192.1 to 198.29.223.254198.29.223.2558,190
240198.29.224.0/19198.29.224.1 to 198.29.255.254198.29.255.2558,190
241198.30.0.0/19198.30.0.1 to 198.30.31.254198.30.31.2558,190
242198.30.32.0/19198.30.32.1 to 198.30.63.254198.30.63.2558,190
243198.30.64.0/19198.30.64.1 to 198.30.95.254198.30.95.2558,190
244198.30.96.0/19198.30.96.1 to 198.30.127.254198.30.127.2558,190
245198.30.128.0/19198.30.128.1 to 198.30.159.254198.30.159.2558,190
246198.30.160.0/19198.30.160.1 to 198.30.191.254198.30.191.2558,190
247198.30.192.0/19198.30.192.1 to 198.30.223.254198.30.223.2558,190
248198.30.224.0/19198.30.224.1 to 198.30.255.254198.30.255.2558,190
249198.31.0.0/19198.31.0.1 to 198.31.31.254198.31.31.2558,190
250198.31.32.0/19198.31.32.1 to 198.31.63.254198.31.63.2558,190
251198.31.64.0/19198.31.64.1 to 198.31.95.254198.31.95.2558,190
252198.31.96.0/19198.31.96.1 to 198.31.127.254198.31.127.2558,190
253198.31.128.0/19198.31.128.1 to 198.31.159.254198.31.159.2558,190
254198.31.160.0/19198.31.160.1 to 198.31.191.254198.31.191.2558,190
255198.31.192.0/19198.31.192.1 to 198.31.223.254198.31.223.2558,190
256198.31.224.0/19198.31.224.1 to 198.31.255.254198.31.255.2558,190

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.